1. Field of the Invention
The present invention relates to a device for multimeasurement of vertical position variation and to a level-setting system equipped with a device of this type.
2. Description of the Prior Art
A measurement of vertical variation in position of one or a number of predetermined points of an industrial or scientific construction or installation, which makes it possible to follow a change in level of these points, often proves essential for good maintenance of said construction or installation. In fact, good operation of a structure such as a dam or an industrial or scientific installation such as a synchrotron is largely dependent on relative stability of its different parts. In point of fact, a construction or installation of this type often extends over a large land area whose structure, composition and hydrographic state may change from one location to another and cause unequal sliding of its strata or heterogeneous land subsidence which disturbs the operation or impairs the strength or good operation of the construction or installation considered. In a scientific installation such as that of a synchrotron, a variation in level by a value of one-tenth of a millimeter can already have an adverse effect on its operation or industrial or scientific exploitation. In order to overcome this drawback, some thought has been given to the possibility of controlling the variation in level of the principal points of an installation of this type by laser sighting. However, these points are often remote from each other or concealed with respect to each other. In order to obtain rapidly or at any moment data relating to the variation in level of these points, each point has to be equipped with a laser emitter and with an associated receiver. Equipment of this type entails the need for substantial capital outlay.
The present invention aims to circumvent these disadvantages by permitting the construction of an economical device for multimeasurement of vertical position variation which is capable of detecting variations of small values of the order of one-tenth of a millimeter and of an economical and effective level-setting system equipped with a device of this type which is capable of carrying out in an industrial or scientific installation even a position adjustment of its principal points by a small value of the order of one-tenth of a millimeter.